High dielectric constant (high-k) transistors in conjunction with metal gates, or “MHK transistors”, are undergoing active development in the industry. However, conventional fabrication techniques for MHK transistors generally result in defects intrinsic to metal contacts. The created during high temperature processing alter the threshold voltage (Vt) for device operation. This is especially acute for p-type devices. Charged oxygen vacancies are one main cause of Vt shifts. In a MHK transistor, any extrinsic oxygen that enters the formed high-k gate layer during subsequent processing changes the electrical properties of the MHK transistor. Conventional fabrication techniques do not effectively overcome these problems.